The invention, in some embodiments, relates to the field of emulsions.
An emulsion is a mixture of at least two normally-immiscible liquids. In an emulsion, at least one liquid, constituting the dispersed phase, is present as a plurality of discrete droplets dispersed in at least one second liquid, constituting the continuous phase.
Typically, emulsifiers are added to an emulsion. Emulsifiers are materials that are soluble in one of the liquids of the emulsion to promote formation and stability of an emulsion. The nature of a specific emulsifier or combination of emulsifiers also assists in determining whether a given mixture will be a water-in-oil (aqueous dispersed phase) or oil-in-water emulsion (non-aqueous dispersed phase).
One specific type of emulsion is the Pickering emulsion. In a Pickering emulsion, the emulsion includes a shell of solid particles located at the interfaces between the dispersed phase droplets and the continuous phase. Pickering emulsions are typically made by combining an oil, a water and solid particles (typically less than 100 micrometers in diameter) and then vigorously mixing, for example in a blender. Depending on the relative amounts of the water and oil, the size of the solid particles and the nature of the solid particles (generally the phase that preferentially wets the particle will be the continuous phase), a water-in-oil or oil-in-water Pickering emulsion is formed, where the presence of the solid particles increases stability of the emulsion by preventing the dispersed phase droplets from coalescing.